Approximating apparatus for surgical jaw structure

ABSTRACT

Approximating apparatus for surgical jaw structure is provided which effects substantially parallel approximation of first and second surgical jaw structure to permit substantially parallel working interaction therebetween. The approximating apparatus includes camming structure for engaging at least one movable jaw of the surgical jaw structure to bias that jaw toward or away from a second jaw structure in a substantially parallel manner. A tissue stop may be provided to more easily guide and protect tissue captured by the jaw structure.

CROSS REFERENCES TO RELATED APPLICATION

This is a continuation of copending application Ser. No. 07/703,625filed on May 21, 1991, which is a continuation in part of Ser. No.07/669,352 filed on Mar. 14, 1991, both now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to approximating apparatus forsurgical instrumentation and more particularly to apparatus whicheffects substantially parallel approximation of the jaw structure forsurgical instrumentation.

2. Description of the Related Art

A wide variety of surgical procedures used today involve surgicalinstrumentation having jaw structure such as, for example, grippers,graspers, dissectors, clamps, cutting elements, stapling elements andtissue measuring devices. In each of these types of jaw structureaffected tissue is captured by the jaws for manipulation. The ease andaccuracy of this tissue capturing step is extremely important if thesurgical procedure is to be carried out in an efficient manner. One typeof jaw structure currently used captures tissue by a pivotal action ofthe jaw structure wherein the jaws close progressively from a pivotpoint outward to the end of the jaw structure. See, for example U.S.Pat. Nos. 3,866,610; 4,243,047; 4,369,788; 4,512,343; 4,572,185;4,590,936 and 4,674,501. This pivotal action can, in certaincircumstances, overcompress captured tissue nearest to the pivot pointwhile undercompressing captured tissue near the ends of the jawstructure. The uneven compression can result in uneven cutting,unintentional tissue trauma, and/or inaccurate tissue measurement orjoining. This is particularly true in endoscopic or laparoscopicprocedures where accessibility is extremely limited. In these proceduresaccuracy and precision are vitally important. Apparatus must be capableof easily and accurately capturing tissue for subsequent manipulationwithout unintentional trauma.

A more accurate and atraumatic way of approximating surgical jawstructure is by parallel approximation. This approach has been utilizedwith some success in the area of surgical clamping. For example, inCooper U.S. Pat. No. 4,931,058 and Blasnik et al. U.S. Pat. No.4,976,721 surgical clamp structure is shown wherein spring loadedparallel clamping jaws are moved together in parallel orientation bycompression of locking structure disposed on an end of the jawstructure. These surgical clamps however are not readily operable inremote or limited visibility applications such as, for example,endoscopic or laparoscopic procedures and do not make use of cammingaction.

Similarly, some surgical stapler designs make use of parallelapproximation to facilitate capture and joining of tissue. For example,U.S. Pat. Nos. 3,269,630; 3,795,034; 4,319,576; 4,442,964; 4,603,693;4,788,978 and 4,930,503 disclose some degree of parallel approximationof anvils and staple cartridge elements. However, these designs aresomewhat bulky and in some cases difficult to manipulate. U.S. Pat. No.3,844,289 shows a scissors type hemostat having L-shaped jaw structurefor capturing tissue therebetween. A clip applier is attached to thehemostat for clipping the captured tissue. In operation, the clipapplier moves substantially perpendicular to the plane of the workingends of the hemostat jaw structure by means of pins and slots to clipthe captured tissue. None of these references utilize camming structureor a camming action to effect substantially parallel approximation ofsurgical jaw structure while maintaining an efficient and simple mode ofoperation for the working ends thereof.

Therefore, it would be highly desirable to have approximating jawstructure for surgical instrumentation which allows for accurate andprecise substantially parallel approximation in remote or limitedaccessibility applications.

Accordingly, it is an object of the present invention to provideapparatus for approximating jaw structure which provides accuratesubstantially parallel capture of subject tissue.

Another object of the present invention is to provide apparatus forapproximating jaw structure for surgical instrumentation which permitsparallel approximation of jaw structure on subject tissue in remote orlimited accessibility conditions.

Other and further objects of the present invention will be explainedhereinafter, and will be more particularly delineated in the appendedclaims, and other objects of the present invention will hereinafterbecome apparent to one with ordinary skill in the art to which thepresent invention pertains.

SUMMARY OF THE INVENTION

The present invention is an approximating apparatus for jaw structure insurgical instrumentation such as, for example, grippers, graspers,dissectors, cutters, measurers, staplers, etc. This approximatingapparatus effects substantially parallel approximation of first andsecond surgical jaw structure to permit substantially parallel workinginteraction therebetween. The approximating apparatus includes cammingstructure engaging at least one movable jaw of the surgical jawstructure to bias that jaw structure toward a second jaw structure. Inone embodiment, a camming plate is provided with parallel diagonalcamming slots formed therein. The camming plate is axially disposed in ahousing or frame mounting a stationary surgical jaw structure. A movablejaw structure is mounted in the housing for substantially parallelmovement perpendicular to the plane of the stationary surgical jawstructure. The movable jaw structure is blocked against axial movementwithin the housing. Camming pins, attached to the movable jaw structure,ride in the parallel diagonal camming slots in the camming plate. As thecamming plate is moved axially within the housing, the movable jawstructure moves perpendicular to the plane of the stationary jawstructure into parallel approximation with the stationary jaw structure.

Other camming structure may be utilized within the scope of the presentinvention to achieve substantially parallel approximation of a movablesurgical jaw structure relative to a stationary surgical jaw structure.For example, camming surfaces may be provided on the movable surgicaljaw structure which are engaged by a camming tube adapted for distal andproximal axial movement around at least a portion of the movable andstationary surgical jaw structure. The camming surfaces on the cammingtube engage the camming surfaces on the movable surgical jaw structureto move it in substantially parallel approximation in a directionperpendicular to the longitudinal plane of the stationary surgical jawstructure.

In particularly advantageous embodiments of the present invention, thecamming surfaces and or slots may be angled for example to widen theinitial distal spacing of the surgical jaw structure to assist in thecapture of tissue. Also, it is contemplated that the approximatingapparatus for the surgical jaw structure can be formed as a separateremovable unit for interchangability with various types of actuatingmeans. For example, approximating tissue measuring jaws could be removedfrom an actuating means and replaced with stapling jaws or cutting jaws,etc.

BRIEF DESCRIPTION OF THE DRAWINGS

For a further understanding of the objects of the present invention,reference is made to the following detailed description of preferredembodiments which is to be taken in connection with the accompanyingdrawings, wherein:

FIG. 1 is a perspective view in cross section of an apparatus inaccordance with the present invention utilizing tissue measuring jawstructure shown in the closed approximated position;

FIG. 2 is a side view in cross section of the apparatus of FIG. 1showing the tissue measuring jaw structure in the open position;

FIG. 3 is an exploded perspective view of the tissue measuring apparatusof FIG. 1.

FIG. 4 is a side view in partial cross section of apparatus inaccordance with the present invention utilizing surgical clamping jawstructure shown in the open position;

FIG. 5 is a perspective view of apparatus in accordance with the presentinvention utilizing surgical stapling jaw structure shown in the openposition;

FIG. 6 is a side view of the apparatus of FIG. 5 removably attached toan actuating device;

FIG. 7 is a side view in cross section of apparatus in accordance withthe present invention utilizing surgical gripping jaw structure shown inthe open position;

FIG. 8 is an end view of the apparatus of FIG. 7 along line 8--8;

FIG. 9 is a side view in cross section of apparatus in accordance withthe present invention as in FIG. 7 shown in the closed position;

FIG. 10 is an end view in cross section of the apparatus of FIG. 9 takenalong line 10--10;

FIG. 11 is a perspective view in partial cross section of apparatus inaccordance with the present invention utilizing surgical cleaving jawstructure;

FIG. 12 is a side view in cross section of the apparatus of FIG. 11 inthe extended open position;

FIG. 13 is a side view in cross section of the apparatus of FIG. 11 inthe open position; and

FIG. 14 is a side view in cross section of the apparatus of FIG. 11 inthe closed position.

FIG. 15 is a side view in partial cross section of an embodiment of thepresent invention utilizing tissue measuring jaw structure with anintegral tissue stop.

FIG. 16 is a side view of the jaw structure of FIG. 15.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to FIGS. 1-14 wherein like parts have been given like indexnumerals and initially to FIGS. 1-3, there is shown approximatingapparatus in accordance with a preferred embodiment of the presentinvention for use in endoscopic tissue measuring instrumentation 20. Astationary first jaw structure 22 is integrally formed on a distal end24 of tubular housing or frame means 26 in axial alignment therewith. Asecond movable jaw structure 28 is movably retained by the tubular framemeans 26 for substantially parallel approximation with the stationaryfirst jaw structure 22. Second movable jaw structure 28 comprises a pairof dog leg frame members 30 having proximal and distal ends 32, 34. Ajaw sleeve 36 overfits both distal ends 34 of the dog leg frame member30 and assists in holding the members together. The proximal ends 32 aredisposed parallel to one another and define a yoke therebetween. A firstcamming pin 40 is inserted through opposing transverse bores 42 formedin the proximal ends 32 of the dog leg frame members 30 and is flushwith the outer surface of the dog leg frame members 30. A second cammingpin 44 is inserted in opposing transverse bores 46 formed proximal toopposing bores 42 in the proximal ends 32 of the dog leg frame members30. Second camming pin 44 extends transversely beyond the outer surfaceof the dog leg frame members 30 and engage a pair of perpendiculargrooves 48 formed in the side walls of tubular frame means 26. Thissecond camming pin 44 prevents longitudinal motion of the second movablejaw structure 28 relative to stationary jaw structure 22 and serves toassist in guiding the second jaw structure 28 in substantially parallelapproximation with the stationary jaw structure 22.

A camming plate 50 having first and second camming slots 52, 54 isaxially positioned in the yoke formed by the proximal ends 32 of dog legframe members 30 for longitudinal movement therethrough. First andsecond camming pins 40, 44 are disposed in first and second cammingslots 52, 54 for longitudinal angular movement therein. In theembodiment shown in FIGS. 1-3 first and second camming slots 52, 54extend diagonally and remain substantially parallel for approximatelyhalf of their height. Thereafter, second camming slot 54 extends in aplane substantially parallel to the longitudinal axis of tubular framemeans 26 while first camming slot 52 continues diagonally. This featurepermits the opening between the distal ends of the first and second jawstructure "A" to be overextended with respect to the opening at theproximal portion of the jaw structure "B". Thus, initial capture oftissue is facilitated by the widened jaw orientation. Thereafter, thejaw structure will reorient to substantially parallel alignment topermit substantially parallel approximation and working interactionbetween the jaws.

In the embodiment of FIGS. 1-3 the tissue measuring device 20 isnormally oriented with the jaw structure in the closed approximatedposition (see FIG. 1). The actuating mechanism for effectinglongitudinal movement of camming plate 50 and thus the substantiallyparallel movement of jaw structure 28 relative to jaw structure 22includes a shaft 56 attached at a distal end 58 to a proximal end ofcamming bar 50, a compression spring 60 and plunger 62 attached to aproximal end 64 of shaft 56. A longitudinal cavity 66 is dimensioned andconfigured in a proximal end 68 of tubular housing 26 to retaincompression spring 60. A distal end 70 of compression spring 60 abutsannular step 72 formed in the tubular frame means 26 while the proximalend 74 of compression spring 60 contacts the distal end 76 of plunger62.

Distal longitudinal movement of plunger 62 compresses spring 60 anddrives shaft 56 axially within tubular frame means 26. A circumferentialflange 78 is formed around the outside of the proximal end 68 of thetubular frame means 26 to assist in compression of plunger 62. Cammingbar 50 is driven in a distal longitudinal direction causing first andsecond camming pins 40, 44 to ride in first and second camming slots 52,54 respectively to open jaw structure 28 relative to stationary jawstructure 22. Since second camming pin 44 is restricted from axialmovement by perpendicular grooves 48, jaw structure 22 and 28 move apartin a substantially parallel orientation. Once the tissue is capturedwithin the jaws 22, 28, the plunger 62 is released and compressionspring 60 serves to reverse the longitudinal direction of shaft 56causing the jaws to close on the tissue. The force of compression spring60 is selected to provide an accurate measurement of tissue thickness,i.e., so as not to cause undue tissue compression.

Where relatively thick tissue (i.e. thicker than about 0.1 inch) is tobe captured and measured, supplemental approximation assist means may beincorporated to assure quick and accurate measurement. In the embodimentof FIGS. 1-3, supplemental approximation assist means, shown generallyat 59, is positioned in slot 63 formed in camming plate 50 and includesa secondary compression spring 61 and fork 65. Both spring 61 and fork65 are dimensioned and configured to fit longitudinally within slot 63with arms 67, 69 of fork 65 extending distally beyond slot 63 to abutand engage the proximal ends 32 of dog leg frame members 30 asnecessary. The force of secondary compression spring 61 is selected soas to provide supplemental approximation assistance to compressionspring 60 when thick tissue is to be measured. Thus, as shown in FIGS. 1and 2, when the endoscopic tissue measuring instrument 20 is closed orapproximated around relatively thin tissue (FIG. 1), arms 67, 69 of fork65 do not engage the proximal ends 32 of dog leg frame members 30.However, referring to FIG. 2, as the second jaw structure 28 is openedrelative to first jaw structure 22, the proximal ends 32 of dog legframe members 30 engage the arms 67, 69 of fork 65 and serve to compresssecondary spring 61 in slot 63. When capture of tissue is completed, thecombined expansion forces of compression spring 60 and secondarycompression spring 61 serve to approximate jaw structures 22 and 28 toprovide a quick and accurate measurement of the captured tissue. Oneskilled in the art will readily appreciate that other types ofapproximation assist means may be incorporated to assist as necessary inthe closure of surgical jaw structure and that such assist means may beadapted to engage and/or assist in closure during any stage ofapproximation or separation of the surgical jaw structure.

In the embodiment shown in FIGS. 1-3 visual measurement apparatus isincorporated into both the proximal and distal ends of tubular framemeans 26. At the distal end, a measuring jacket 80 is positioned overdog leg frame members 30 and gauges the vertical position of movablesecond jaw structure 28 relative to first jaw structure 22. A window 82is provided in tubular frame means 26 adjacent measuring jacket 80 tofacilitate reading the measurement. Graduations may be provided onjacket 80 which translate into thickness measurements of the capturedtissue. At the proximal end of tubular frame means 26 a second window isprovided to accurately determine the axial position of plunger 62relative to frame means 26. Graduations may be provided on plunger 62which translate into thickness measurements of the captured tissue.

This embodiment of the approximating apparatus utilized in a tissuemeasuring configuration is designed to measure the thickness of tissuecaptured between the jaw structure 22, 28. One skilled in the art willreadily appreciate that the instrumentation can be configured to makeother tissue measurements such as, for example, inner diameters ofhollow body organs simply by utilizing the outer surfaces of the jawstructure as the measuring point. Thus the jaw would be inserted intothe hollow organ and expanded in a substantially parallel manner untilthe outer surfaces of the jaw structure contacts the inner surface ofthe hollow organ. A measurement of the inner diameter of that organ canthen be generated.

In particularly advantageous embodiments of the present invention,tissue stop means may be incorporated into the jaw structure. In theembodiment of FIGS. 15 and 16 an integral tissue stop 37 is incorporatedinto a lower proximal end of jaw sleeve 36.

The tissue stop 37 inhibits captured tissue (not shown) from enteringthe interleaved area between the proximal ends of first and second jawstructure 22, 28. It is envisioned that tissue stops similar to thatdescribed above can be used with other embodiments of the presentinvention discussed below.

Various known actuating mechanisms may be utilized to drive cammingplate 50 including, for example, axial screw type structure, foldinghandles, scissors or pistol grip type structures capable of effectingaxial longitudinal movement of the camming bar. Further, the tissuemeasuring device 20 shown in FIGS. 1-3 is designed and configured foradvantageous use in endoscopic or laparoscopic procedures wherein thetubular frame means 26 is inserted through a cannula for manipulationinside an enclosed body cavity. Various other housing configurations arepossible for use not limited to insertion through a cannula. Thesehousing configurations are within the scope of one skilled in the art.

Referring to FIG. 4, an approximating apparatus in accordance with thepresent invention is shown in conjunction with surgical clamping jawstructure. This approximating apparatus is substantially similar to thatdiscussed above with respect to the tissue measuring device. Astationary first surgical clamping jaw 86 is attached to housing orframe 88. A movable second surgical clamping jaw 90 is retained inhousing 88 for substantially parallel approximation toward stationaryfirst surgical clamping jaw 86. The second surgical clamping jaw 90comprises a distal end 92 having a working clamping surface 94 formed onan inner surface thereof matable in opposing relation to a correspondingworking clamping surface 96 formed on an inner surface of the stationaryfirst surgical clamping jaw 86. The proximal end 98 of the secondsurgical clamping jaw 90 forms two parallel longitudinal arms 100forming a yoke therebetween. A first camming pin 102 is inserted throughopposing transverse bores 104 formed in the parallel longitudinal arms100 of the second surgical clamping jaw 90. A second camming pin 106 isinserted through opposing transverse bores 108 formed in the parallellongitudinal arms 100 of the second surgical clamping jaw 90 proximal ofopposing bores 104. At least one of the camming pins 102, 104 ispositioned within perpendicular parallel grooves 110 formed in thesidewalls of frame means 88 to prevent axial movement of the secondsurgical clamping jaw 90 relative to the first surgical clamping jaw 86.

A camming bar 112 having first and second camming slots 114 and 116 isaxially positioned in the yoke formed by parallel longitudinal arms 100for longitudinal movement therethrough. First and second camming pins102, 106 are disposed in first and second camming slots 114, 116respectively for longitudinal angular movement therein. In theapproximating apparatus of FIG. 4, camming slots 114 and 116 extenddiagonally and remain substantially parallel throughout their length.Thus, in this configuration the first and second surgical clamping jawsremain substantially parallel throughout their range of relativemovement.

In operation, an appropriate actuating mechanism (not shown) is engagedto drive camming bar 112 in a longitudinal distal direction. Thislongitudinal distal movement of the camming bar 112 causes first andsecond camming pins 102, 106 to move in parallel diagonal camming slots114, 116 causing the substantially parallel approximation of the secondsurgical clamping jaw relative to the first.

The apparatus of FIGS. 5-6 utilizing surgical stapling working ends mayadvantageously be used in conjunction with the tissue measuring deviceof FIGS. 1-3, particularly where both the tissue measuring and staplingdevices are interchangeable with and actuatable by a single actuatingmeans. For example, prior to stapling, the tissue measuring device ofFIGS. 1-3 is inserted onto an appropriate actuating means and used tocapture tissue and generate a size measurement thereof. Based on thatgenerated measurement, a staple size is selected which will accuratelyand efficiently join the tissue. Thereafter, the surgical stapling jawstructure having a staple cartridge therein with staples of apreselected size is inserted onto the actuating means and positioned tostaple the tissue.

It is readily apparent to one skilled in the art that the angularconfiguration of the camming slots 114 and 116 may be varied, eithercollectively or individually, to achieve different substantiallyparallel approximation sequences. For example, as shown in FIGS. 1-3above, one slot may be configured to allow for an initially wideropening at the distal ends of the jaws to facilitate capture of tissue.It is possible to orient the slot configurations at a different angle toclose the distal ends of the jaws first, prior to final approximation,in order to avoid loss of the captured tissue out of the distal end.

Referring now to FIGS. 5-6, approximating apparatus in accordance withthe present invention is shown configured for use in a surgical staplerdevice shown generally at 118. A first stationary jaw structure 120comprises a substantially U-shaped channel having a proximal end 122 anda distal end 124. A staple cartridge 126 is positioned within theU-shaped channel at the distal end of the first stationary jaw structure120. Second movable jaw structure 128 comprises an anvil 130 formed on adistal end and a first and second sloped camming surface 132, 134 formedon an upper portion of a proximal end thereof. The first and second jawstructure are interconnected by means of a pair of transverse pins 136,138 which extend through the proximal end of second movable jawstructure 128, which pins are retained in two pairs of correspondingvertical parallel slots 140, 142 formed in vertical side walls of theproximal end 122 of the first stationary jaw structure 120. Thus thesecond movable jaw structure 128 fits within the U-shaped channel offirst stationary jaw structure 120 for substantially parallel reciprocalmotion therein.

A camming housing or frame 144 surrounds the respective proximal ends ofthe first and second jaw structure 120, 128 and is mounted forlongitudinal reciprocal motion relative to the jaw structure. First andsecond camming surfaces 146, 148 are formed in an upper portion of thecamming housing 144 and respectively engage first and second slopedcamming surfaces 132, 134 formed in the proximal end of second jawstructure 128. A leaf spring 150 is positioned between the first andsecond camming surfaces 132, 134 and engages a shelf 152 formed in avertical side wall of the proximal end of the first stationary jawstructure 120. This leaf spring 150 serves to bias apart the respectivedistal ends of the first and second jaw structure 120, 128.

In operation, an actuating means, shown generally at 154 in FIG. 6, isactivated to move camming housing 144 in a distal longitudinal directionrelative to the first and second jaw structure 120, 128. This actioncauses first and second camming surfaces 146, 148 on the camming housing144 to respectively engage first and second sloped camming surfaces 132,134 on the proximal end of the second movable jaw structure 128. Sincetransverse pins 136, 138 in vertical parallel slots 140, 142 allow foronly substantially parallel approximating motion, the second movable jawstructure 128 is moved in a substantially parallel fashion relative tofirst stationary jaw structure 120 resulting in approximation of anvil130 and staple cartridge 126. Once tissue to be stapled is captured andthe jaws are approximated, the staples can be fired and tissue cut usingknown structure and techniques.

In the apparatus shown in FIGS. 5-6, the first and second jaw structure120, 128 and the camming housing 144 are formed as a unit and areremovable from the actuating means 154 simply by applying a longitudinaldistal force sufficient to disengage the unit therefrom. Thus, a widevariety of different types of jaw structure, i.e. clamps (FIG. 4),tissue measurers (FIG. 1), grippers (FIG. 7), etc., may be utilized witha single actuating means.

FIGS. 7-10 show a sequence of closure for an approximating apparatussubstantially similar to that described above with respect to FIGS. 5-6with the exception that the first and second jaw structure are providedwith gripping ends 156, 158 instead of an anvil and staple cartridge. InFIGS. 7-8 the first stationary jaw structure 160 and the second movablejaw structure 162 are disposed in the open position with theirrespective distal ends, formed as gripping ends 156, 158, spaced apart.Camming housing 144 is driven longitudinally distally such that cammingsurfaces 146, 148 on the camming housing 144 engage and drive slopedcamming surfaces 132, 134, respectively, on the proximal end of thesecond movable jaw structure 162. This causes the second movable jawstructure 162 to move in substantially parallel approximation motionguided by vertical slots 140, 142 and transverse pins 136, 138. Uponreaching its full longitudinal distal travel (FIGS. 9-10) cammingsurfaces 146, 148 move onto locking flats 164, 166 formed at the top ofthe sloped camming surfaces 132, 134. Thus, the gripping ends 156, 158are maintained in close parallel approximation around subject tissue.

As in previous embodiments, the approximating apparatus of FIGS. 7-10may be removable from and insertable into a wide variety of actuatingmeans.

FIGS. 11-14 disclose approximating apparatus in accordance with apreferred embodiment of the present invention utilizing cutting jawelements. Referring to FIG. 11, a first movable jaw structure 168 isshown including a distal end having cutting structure 170 formed thereinand a proximal end having first and second camming surfaces 172, 174 ona top portion thereof and first and second longitudinally disposedcamming chambers 176, 178 formed in a sidewall portion thereof. Acamming housing or frame 180, shown in cross section in FIG. 11,encloses a portion of the proximal end of the first movable jawstructure 168 and has first and second camming bosses 182, 184 disposedin opposing sidewalls adjacent to first and second camming chambers 176,178 in first movable jaw structure 168. Camming housing 180 alsoincludes first and second camming surfaces 186, 188 disposed adjacentfirst and second camming surfaces 172, 174 on the proximal end of thefirst movable jaw structure (see FIGS. 12-14). A second stationary jawstructure 190 is disposed within camming housing 180 and interfits withfirst movable jaw structure 168 for relative substantially parallelapproximation therewith. The proximal end of the stationary jawstructure 190 is prevented from rotational motion by locking pin 196. Acutting block 192 is disposed on a distal end of jaw structure 190 forsubstantially parallel working interaction with cutting structure 170.

In the embodiment of FIGS. 11-14, first movable jaw structure 168 isinitially disposed in an open extended orientation relative to secondstationary jaw structure 190 (FIG. 12). First camming bosses 182 arepositioned proximally beneath first camming chambers 176 while secondcamming bosses 184 are disposed in a pivot chamber 194 formed in aproximal portion of second camming chambers 178. As seen in FIG. 12,this configuration allows the opening between the distal ends of cuttingstructure 170 and cutting block 192 ("A" in FIG. 12) to be wider thanthe opening between the proximal ends of cutting structure 170 andcutting block 192 ("B" in FIG. 12). Thus initial tissue capture isfacilitated.

In operation, camming housing 180 is moved longitudinally distally byactuating means (not shown) relative to first and second jaw structure168, 190. As the camming housing 180 moves distally, second cammingbosses 184 are freed from pivot chamber 194 and camming surfaces 186 and188 respectively engage camming surfaces 172 and 174 formed in theproximal end of first movable jaw structure 168. This camming engagementeffects a substantially parallel approximation of the cutting structure170 and the cutting block 192 (See FIGS. 13-14). Camming bosses 182, 184serve to guide this substantially parallel approximation as they travelalong the diagonally sloping surface of the first and second cammingchambers 176, 178.

This substantially parallel approximation of the jaw structure permitsan accurate and controlled separation of the tissue without the unevenand progressive shearing action inherent in conventional scissorsstructure.

To the extent not already indicated, it also will be understood by thoseof ordinary skill in the art that any one of various specificembodiments herein described and illustrated may be further modified toincorporate features shown in other of the specific embodiments. Forexample, first and second jaw structures may both be adapted to movetransverse to the longitudinal axis of the device to effect parallelapproximation by providing complementary camming means for each jawstructure.

The invention in its broader aspects therefore is not limited to thespecific embodiments herein shown and described but departures may bemade therefrom within the scope of the accompanying claims withoutdeparting from the principles of the invention and without sacrificingits chief advantages.

We claim:
 1. Apparatus for approximating jaw structure of surgicalinstrumentation comprising:a tubular endoscopic housing defining alongitudinal axis, a distal end and a proximal end, said housing havingan axial bore in said distal end; first jaw structure extending fromsaid distal end of said endoscopic housing and stationary with respectthereto, said first jaw structure having a distal working end and aproximal end; second jaw structure disposed in spaced relation to andconnected with said first jaw structure, said second jaw structurehaving a distal working end for substantially parallel workinginteraction with said first jaw structure and a proximal end, said firstand second jaw structure being disposed substantially parallel to thelongitudinal axis of the surgical instrumentation and interconnected forsubstantially parallel approximation; approximating means, at leastpartially disposed in said axial bore, having camming structure forcamming said second jaw structure in substantially parallel relationwith respect to said first jaw structure to permit working interactionbetween said distal working ends of said first and second jaw structure;and tissue stop means disposed proximally from said distal working endsof said jaw structures for maintaining captured tissue within saiddistal working ends, wherein said approximating means includes: acamming plate axially slidable within said axial bore, said cammingplate having a first and second camming slot formed therein; a firstcamming pin disposed in said first camming slot and transversely mountedin the proximal end of said second jaw structure, said first camming pinengaging transverse slots in said endoscopic housing to restrict axialmovement of said distal working end of said second jaw structure; asecond camming pin disposed in said second camming slot and transverselymounted parallel to said first camming pin in the proximal end of saidsecond jaw structure such that axial movement of said camming platerelative to said endoscopic housing causes substantially parallelapproximation of said distal working ends of said first and second jawstructure.
 2. Apparatus as in claim 1 wherein said working ends of saidfirst and second jaw structure collectively comprise surgical clampingjaws.
 3. Apparatus as in claim 1 wherein said working ends of said firstand second jaw structure collectively comprise surgical gripping jaws.4. Apparatus as in claim 1 wherein said first jaw structure includes astaple cartridge portion having a plurality of staples disposed thereinand said second jaw structure comprises anvil structure having a stapleforming surface thereon.
 5. Apparatus as in claim 1 wherein at least oneof said camming slots includes a substantially axially aligned portionsuch that when at least one of said camming pins is disposed in saidsubstantially axially aligned portion, said distal working ends of saidfirst and second jaw structure move into non-parallel alignment tofacilitate capture of tissue.
 6. Apparatus as in claim 1 furthercomprising actuating means axially disposed in said endoscopic housingfor driving said camming plate axially therein.
 7. Apparatus as in claim6 further comprising a spring loaded actuating means for axially movingsaid camming plate to open said distal working ends of said first andsecond jaw structure in a substantially parallel manner.
 8. Apparatus asin claim 1 wherein said first and second jaw structure collectivelycomprise tissue measuring structure.
 9. Apparatus as in claim 1 whereinat least one of said jaw structures extends beyond an outer perimeter ofsaid endoscopic housing when in a substantially open position. 10.Apparatus for approximating jaw structure of surgical instrumentationcomprising:a tubular endoscopic housing defining a longitudinal axis, adistal end and a proximal end, said housing having an axial bore in saiddistal end; first jaw structure extending from said distal end to saidendoscopic housing and stationary with respect thereto, said first jawstructure having a distal working end and a proximal end; second jawstructure disposed in spaced relation to and connected with said firstjaw structure, said second jaw structure having a distal working end forsubstantially parallel working interaction with said first jaw structureand a proximal end, said first and second jaw structure being disposedsubstantially parallel to the longitudinal axis of the surgicalinstrumentation and interconnected for substantially parallelapproximation; and approximating means, at least partially disposed insaid axial bore, having camming structure for camming said second jawstructure in substantially parallel relation with respect to said firstjaw structure to permit working interaction between said distal workingends of said first and second jaw structure; and tissue stop meansdisposed proximally from said distal working ends of said jaw structuresfor maintaining captured tissue within said distal working ends, whereinsaid working ends of said first and second jaw structure collectivelycomprise tissue measuring structure.
 11. Apparatus as in claim 10wherein said tissue stop means comprises at least one crossmember formedin said second jaw structure.
 12. Apparatus as in claim 10 wherein saidtissue stop means comprises at least one crossmember formed in saidfirst jaw structure.
 13. Apparatus as in claim 8 further comprisingmeasurement indicating means for displaying a visual measurement oftissue.
 14. Apparatus as in claim 8 wherein the tissue measuringstructure is adapted to measure tissue compressed between said first andsecond jaw structure.
 15. Apparatus as in claim 8 wherein the tissuemeasuring structure is adapted to measure tissue surrounding said firstand second jaw structure.